docs: def command(self):
          """Returns a string representing the command you have to type to obtain the same packet"""
          f = []
          for fn,fv in self.fields.items():
              fld = self.get_field(fn)
              if isinstance(fv, Packet):
                  fv = fv.command()
              elif fld.islist and fld.holds_packets and type(fv) is list:
                  #fv = "[%s]" % ",".join( map(Packet.command, fv))
                  fv = "[%s]" % ",".join([ Packet.command(i) for i in fv ])
              else:
                  fv = repr(fv)
              f.append("%s=%s" % (fn, fv))
          c = "%s(%s)" % (self.__class__.__name__, ", ".join(f))
          pc = self.payload.command()
          if pc:
              c += "/"+pc
          return c